The present application relates to battery systems and battery modules (e.g., for use in vehicles such as hybrid electric or electric vehicles) and more specifically, to a buss bar that helps manage and reduce stresses on battery or cell terminals within a battery module.
It is known to provide batteries for use in vehicles such as automobiles. For example, lead-acid batteries have been used in starting, lighting and ignition applications. More recently, hybrid vehicles have been produced which utilize a battery (e.g., a nickel-metal-hydride battery) in combination with other systems (e.g., an internal combustion engine) to provide power for the vehicle.
It is known that different hybrid vehicles have different power needs and may require different numbers of batteries to meet those power needs. It is also generally known to connect a number of batteries or cells using buss bars to form a battery module. A buss bar may, for example, connect a terminal on a first cell to a terminal on a second cell. The buss bar may be secured using a variety of methods, including mechanical fasteners (e.g., screws, etc.), welding (e.g., laser welding, etc.), and so on, often forming rigid connections between the terminals of various cells.
One problem associated with some buss bars is the stress applied to the battery system and battery module resulting from vibration and/or manufacturing tolerances and temperature changes. For example, a hybrid electric vehicle may use a battery module that includes a number of individual cells that are interconnected serially by buss bars. As the vehicle travels, vibratory forces on the cells are transmitted between cells via the buss bars, resulting in undesirable stresses being applied to the cell terminals and the interfaces between the terminals and the buss bars. Furthermore, the cell terminals may experience additional stresses due to imperfect manufacturing tolerances that result in variations in buss bar dimensions, cell dimensions, the distances between terminals, etc. Each of these stresses can deteriorate the connections between the terminals and buss bars.
Another problem associated with battery modules including buss bars is the possibility of the short circuit or shock between the high voltage circuit and the buss bars, especially when a battery is damaged due circumstances such as a vehicle crash. Yet another problem associated with battery modules including buss bars is the difficulty in measuring conditions such as voltage and temperature of cells.
Accordingly, it would be advantageous to provide a buss bar that has a portion or feature that is configured to better absorb, dampen, reduce, and/or eliminate the stresses on individual cells within a battery module.
Accordingly, it would also be advantageous to provide a buss bar that is substantially insulated or otherwise covered to at least partially electrically isolate the buss bars while providing access points for coupling the buss bars to the terminals.
It would also be advantageous to provide a buss bar including voltage sensing leads to monitor voltage conditions of cells for safety and effective operation.